作为近年的研究热点，具核梭杆菌在大肠癌中的研究日益增多，而其与表观遗传学调控（尤其是microRNA）的关系及机制则罕有研究。我们的芯片数据首次发现具核梭杆菌可以差异性调节mir-514-b的不同成熟体；功能实验提示miR-514-b-3p及miR-514-b-5p在大肠癌浸润转移中发挥截然相反的作用。其中具核梭杆菌差异性调节mir-514-b不同成熟体在大肠癌浸润转移中的作用及机制为我们感兴趣的科学问题。本研究欲从细胞实验、动物模型及临床标本等方面1.探明不同标本中具核梭杆菌、miR-514-b-3p、miR-514-b-5p表达关联性及其与临床特点间的关系；2.阐明具核梭杆菌对miR-514-b不同成熟体的差异性调节及机制；3.明确miR-514-b不同成熟体在大肠癌中的不同作用及机制。本研究的开展将进一步丰富肠道菌群在大肠癌发浸润转移中的表观遗传学研究并为今后的防治策略提供科学依据。

As a research hotspot in recent years，the research on Fusobacterium nucleatum in colorectal cancer is increasing. However, the relationship and underlying mechanism between Fusobacterium nucleatum and epigenetics, especially microRNA, is rarely studied. In our previous research，we found that Fusobacterium nucleatum could differentially regulate miR-514-b-3p and miR-514-b-5p, distinct mature products of mir-514-b. Further functional experiment suggested that miR-514-b-3p and miR-514-b-5p had inverse effects on invasion and migration in colorectal cancer cells. Therefore, in this study we will focus on the role of miR-514-b-3p and miR-514-b-5p in CRC and the mechanism by which Fusobacterium nucleatum differentially modulates miR-514-b-3p/miR-514-b-5p. Based on our preliminary data we will 1. evaluate the clinical significance of Fusobacterium nucleatum, miR-514-b-3p and miR-514-b-5p; 2. demonstrate the mechanism by which Fusobacterium nucleatum induces differentially modulation of miR-514-b-3p and miR-514-b-5p; 3. explore the roles and mechanism of miR-514-b-3p/miR-514-b-5p in CRC. In a word, our research may enrich epigenetic research and provide scientific basis for molecular diagnosis and treatment of CRC.